Overview
- The ETH Zurich life‑cycle study, publicized in coverage on August 12–13, 2026, models an integrated calcium‑looping direct air capture system that could cut cement’s climate impact by up to 78 percent by 2050 and reach 85–96 percent CO₂‑removal efficiency depending on the power mix.
- Calcium‑looping uses the same chemistry as cement production: limestone is calcined to quicklime, water converts quicklime to a material that soaks up atmospheric CO₂, and that CO₂ is then compressed for underground storage while the rebuilt limestone returns to the plant.
- Heirloom Carbon Technologies supplied industrial data for the analysis and currently operates a commercial calcium‑looping plant in California that captures about 1,000 tonnes of CO₂ per year and plans a larger facility in Louisiana.
- The net climate benefit depends on low‑carbon electricity because the process is energy intensive, and scaling will require large electric kilns, expanded CO₂ transport and storage infrastructure, capital investment, and policy incentives to be economically viable.
- Cement makes roughly 5–8 percent of global CO₂ emissions so the approach could shift a major industrial source toward net removal if larger pilots, cost studies, grid decarbonization, and regulatory support follow.